But this isn’t news to him. From the moment the composer-lyricist started winning up-and-comer awards after finishing NYU Tisch’s musical theater graduate program in 2005, Iconis has been told time and time again that he’s on the verge of his big break.

He was supposed to make it in 2008, when his rock musical revue “Things to Ruin” garnered a rare rave in The New York Times and later got its own cast recording. Two years later, he was supposed to catch fire when his spaghetti western musical “Bloodsong of Love” played at Ars Nova and earned three Drama Desk Award nominations. In 2016, The Times remarked that Iconis has “been circling Broadway for a number of years without yet landing.”

“I’ve been at this place for so long, where everyone says to me, ‘Oh, you’re about ready to explode. And when you do, it’s gonna be so easy and you’ll be stable,’” Iconis says. But each of his heavy momentum projects eventually fizzled out without Broadway or, in some cases, even off-Broadway runs.

So maybe it’s the built-up good karma of would-be and should-be breaks that’s brought Iconis to the mouth of the volcano he’s at today. Iconis is the mastermind behind the internet’s favorite musical, “Be More Chill,” which opened off-Broadway, at the Pershing Square Signature Center, last month. The show (with a book by Joe Tracz) is based on Ned Vizzini’s novel of the same name about teens and a supercomputer that teaches them how to be more ... cool.

And thanks to a viral cast album — over 150 million streams worldwide — “Be More Chill” went from an overlooked show to something of a musical theater miracle. Three years after originally playing a single month’s worth of performances at a small theater in Red Bank, New Jersey, “Be More Chill” debuted in New York — with an eight-week off-Broadway run that sold out before it even opened.

Iconis is currently juggling all these projects and more, working to bring his newer work to New York for the first time and revive old shows that he thinks could still get their due. And while creative work like this is rarely stable, Iconis counts living off of musical theater — though it’s sometimes hand-to-mouth — as an accomplishment in itself.

Iconis is married to the theater actress Lauren Marcus (“Brooke” in “Be More Chill”), and for the past few months, the pair have either been together in rehearsals and performances, or slowly getting settled into their new apartment, which happens to be very close by the theater.

Iconis’s life seems to revolve around the theater district. The couple’s so-called “break” from work was a marathon viewing of “Angels in America” on Broadway. He doesn’t fantasize much about vacations, let alone take many.

“I should,” he says. “If things are going really well, then I feel like, I’ve been working for 12 years for things to go well, so I want to take advantage of that opportunity. And if things go poorly, I feel like, I can’t leave now, things are going poorly!”

Self-described as a lover of neckties and “the guy with the big eyebrows,” Iconis frequently sports stylish suits and thick glasses. But a few songs into a live performance, his well-coiffed black hair will succumb to his pounding on the piano, starting with a single Superman curl dropping to his forehead and ending with a mess of dark hair flopping along to the rhythm — all this assuring the audience that they are, in fact, at an American Songbook-worthy rock show.

And though Iconis fans scream like groupies at the stage door and at post-show meet-and-greets, their heartfelt hysteria is focused and powerful. “They’re so brave in a way I never was,” Iconis says. “The things that people will come up and say to me — I still couldn’t do that to someone who I only knew as an artist whose work I liked.”

Because he’s written a show that deals with teenage anxiety and depression, fans often approach him and the stars of the show with personal and emotional stories.

“If someone’s crying to you and talking about how this thing that you’ve done has really affected their life, we’re not gonna be like, ‘OK, sorry, next picture!’” Iconis says. “We just need to listen. That equals meet and greets that are like two hours and 15 minutes long.”

But despite the unprecedented method and degree of the show’s success, Iconis is still hesitant to bet on himself. Perhaps partly because the New York theater world is hesitant to wager on anything unproven.

“Everyone is talking about ‘Be More Chill’ like we’re going to be at the Signature and then go on to something else, be that Broadway or another off-Broadway run, or a tour or whatever,” he says. “I’ve been disappointed in such extraordinary ways so many times, that I just can’t get myself to be like, this is it.”

Iconis says this with a smile — not bitterly or lacking appreciation of the support “Be More Chill” has received, but with a candid desire for self-protection. Because even when you’ve written a mega-popular musical and it’s finally playing in New York, the future is always uncertain.

What’s killed some of his past shows, Iconis says, is a bad review in The Times. And The Times review for “Be More Chill” was certainly less-than-glowing. But the day after it appeared, the Signature announced a one-week extension of “Be More Chill,” and the eight extra performances sold out in hours.

While still in rehearsals, Iconis couldn’t shake the feeling that they needed a good review in The Times to move on to the next step — in particular, to transfer to Broadway, which could yet happen. A show needs a reason to be on Broadway, Iconis says, be that a strong property like “Mean Girls,” a big Hollywood star, or, in this case, a good review from Ben Brantley.

“But maybe I’m wrong,” he says. “Maybe the reason is being the internet’s favorite musical.”